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Note added June 29 & September 4, 2014: Before making any repairs on your own Saturn fuse box, you should look at References 1 and 3, which indicate that the problem may have been the infamous “F5” all along. See also comments made in Reference 2. The remainder of this post remains as originally written so that you can see the process involved and the evolution in my own thinking.
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If you’re looking for Volvo or SU content, you won’t find either in today’s post, so you might want to stop reading now, or skip to a different post.

Today I’d like to show how to repair a fuse box for a 1998-1999 Saturn S-Series. The specific vehicle is a 1999 Saturn SL-2, which my wife inherited from her mother (much to my chagrin).

The information to follow is probably applicable to other Saturn years and models, but since I really don’t know much about Saturns (and don’t want to) I can only say with certainty that the three Saturn fuse boxes that I have repaired, one GM Part Number 21024337 from a 1998 S-Series, and two GM Part Number 21024757 from my wife’s 1999 SL-2, are identical in fit, form, and function and are completely interchangeable in all respects.

There are some extremely minor internal differences, but those are inconsequential, other than that the 1998 variety might be a smidgen easier to repair due to less internal plastic to get in the way of running replacement wires. Unfortunately, I didn’t think to take any pictures to highlight those differences, but they really are of no importance.

About two years ago, we began to have problems with my wife’s 1999 Saturn SL-2 dying for no apparent reason, then eventually restarting and running for a while. This happened repeatedly, over a year or more. All attempts to identify and fix the problem were fruitless. Eventually, about one year ago, it just plain wouldn’t run any more, and we had to do something.

It took several months of on-again, off-again efforts, but finally, around August of 2013, we were able to figure out that the fuse box had an internal defect. We then purchased, off e-bay, a fuse box from a 1998 S-series. This fuse box had a different part number, but it was cheap, and we figured it just might work. It didn’t. Same problem. So, we then purchased, from a junkyard in Kansas that specializes in Saturns, a fuse box from a 1999 SL-2 that actually worked…. for roughly 4 months, then the same problems returned.

The Kansas junkyard seems to be a good place to deal with. Here’s a link:

At that point, we were zero for three. We had three identical failures of three essentially identical parts, and we weren’t eager to buy another used, high-mileage, part that would probably suffer the same failure in short order, if it hadn’t already. And a new part is no longer available, so I began to look into repairing our existing fuse box. It turned out to be not so simple, but after roughly 60-80 hours of work I have successfully repaired, and tested, all three of those fuse boxes. So, now I have two spares that I would be willing to sell, if anyone is interested. I am confident enough of the repairs I made that I would warrant them for life.

Here’s a frontal shot of the P/N 21024757 that we purchased from the Kansas yard:

The two 6mm screws (with 10mm hex heads) that hold the fuse box together have been removed; that is necessary before the internals can be removed for repair.

Some of the remaining photos are going to look a bit funny, as if the parts are hanging upside down from the ceiling. That’s because, when I took the pictures, I wasn’t considering writing a blog, or that I just might want to always take pictures from the same orientation, for clarity. So, I just shot pictures so that I’d have enough information to show me how to reassemble the things, without regard to which side up the parts were.

Now, for clarity (I hope) I have rotated all the pictures such that the top of the fuse box is always toward the top of the picture. That results in some of them looking as if they’re hanging down from the ceiling. So be it.

Next shot, a view of the back of the fuse box. The left side of the photo would be oriented toward the front of the car, and this view would be as the fuse box would be seen from the driver’s footwell area (after removing all the various connectors and wiring):

It’s a bit tough to see, but there’s some burning and melting around the third pin from the bottom on the left side. Pin No F5 per GM’s labeling. It’s the third pin up, but it’s located in the 5th row of pins. You may be able to make out the “5”, or at least the “4” below it and the “6” above it.

Next shot, identical to the above, except that it shows some things more clearly, and some things less clearly:

So, pick the picture that shows you what you want to see; they’re otherwise identical.

After some further disassembly (which will be detailed later, on a different fuse box) the innards were extracted and the pins labeled. Here’s a shot of my pin numbering system:

Once again, this is a view of the rear of the fuse box, the side that is facing the driver’s footwell. My numbering system, shown at the left and right, mostly matches GM’s numbering. My lettering system, shown at the bottom, is very different from GM’s system of lettering and numbering, shown at the top and to the left of center. I had to have a consistent (and unique) pin designation that covered all the pins, and GM’s system was neither, so get used to my designations; you will be needing them.

I use letters “A” through “T”, going from left to right, as seen from the driver’s footwell area. “A” would be physically located toward the front of the vehicle. And I use numbers from 1 through 12, going from bottom to top, the same as GM uses on the two side connectors. But they use something entirely different on the central connectors. Ignore GM’s system and use mine.

If you look closely, you may see some melting around the aforementioned Pin F5 (by GM’s nomenclature) on the left side. I will now start referring to this pin by my own nomenclature, specifically “A5”, so let’s try to forget about “F5” forevermore.

Next is a photo of the “different” fuse box that I just promised you. It’s just like the two immediately preceding photos, except that its state of disassembly is intermediate between those two shots.

The sharp-eyed among you might have noticed a bit of butchery at the left side of the above picture that does not appear in the earlier photo. I confess; I did that, and this is actually not the same fuse box as shown in the previous picture; it is the original one from our 1999 Saturn. But, it’s the same view of the same stuff as the other fuse box has. And Pin A5 shows some melting, also. The butchery was a result of my being overly eager (a year and a half earlier) to get inside the fuse box and not thinking it through first. I should have removed those two previously mentioned 6mm screws; then it would have come apart easily. This is the fuse box that has been re-installed in our own Saturn, so if anyone decides he might like to buy one of the two repaired spares, they are both still in pristine condition, visually, and the innards are better than new. A lot better than new.

Next is the same thing, but with a few connectors and one more piece of plastic removed:

Yes, this looks as if it’s hanging from the ceiling. Get used to it; there will be more.

Notice in this picture that Pin A5 (formerly F5) as well as the top four pins in that same leftmost column, (Pins A9 through A12 by my designation) are all brass-colored, whereas most of the pins are silver-gray. This is an important distinction between all those pins.

The silver-gray pins are each common to the two sides of the fuse box, the two pins, one on each side, being one continuous piece of metal; if you have electrical contact with one side, you have electrical contact with the other side, because they’re the same thing. But each of the brass-colored pins exists on only one side of the fuse box. Wherever you see a brass-colored pin on one side of the fuse box, there is no pin at all on the other side.

Another important distinction between the two types of pins is that the silver-gray ones are, in general, connected together using copper wires that are clipped into V-grooves in the pins, whereas the brass-colored ones are made of continuous pieces of metal, with no copper wire connections whatsoever. The brass-colored ones are solid steel and should never fail electrically. I initially said “will never fail”, but absolute statements are always risky. I would give their failure about the same probability as cows on the moon. It is the silver-gray pins that suffer the failures and need the repairs.

So, when you look at Pin A5 (F5 by GM’s designation) and see that melted plastic around it, do not be deceived. The plastic melts there because of the high current through the pin, and not because of a bad electrical connection. The melting that you may see around that pin is a red herring, neither a cause nor a symptom of the electrical failure that these fuse boxes suffer. It is totally irrelevant. The failures occur only at the silver-gray pins and their V-groove connections to the copper wires.

Now I’ll explain how you can be sure that Pin A5 (F5 by GM’s designation, but never again by me) is not the cause of your car’s not running. To fully understand the explanation, you will probably have to read most of this post, study the pictures and their descriptions, then come back and re-read this explanation; it should then make more sense.

Here’s a photo of the fuse box cover from my wife’s 1999 Saturn SL-2:

As explained below, I have carefully traced all the internal connections of our Saturn’s fuse box. Pin A5 connects to the following pins and only the following pins: C5, E4, E5, G1, and G5. Pin C5 supplies power to the left side of the 10 amp fuse labeled “CHIME”. Pin E5 supplies power to the left side of the 20 amp “LIGHTER” fuse, and Pin G5 powers the left side of the 20 amp “LOCKS” fuse. Pin E4 powers the right side of the 10 amp “BODY” fuse, and Pin G1 supplies power to the “+” terminal of the Fuel Pump Relay.

Therefore, if there is power to any one of terminals C5, E4, E5, G1, or G5, your problem is not with Pin A5. If either your cigarette lighter, or locks, or warning chime works, then your problem is not with Pin A5. If you have power to the “+” terminal of your Fuel Pump Relay, then your problem is not with Pin A5. So, the easiest way to check and verify that Pin A5 is not involved in your problem is to just check to see if your cigarette lighter works. If it does, then Pin A5 is not your problem.

If the cigarette lighter doesn’t work, then you will have to investigate a bit further, but I think you’ll find that you have power at all the terminals mentioned here, specifically: C5, E4, E5, G1, and G5. The locations of those terminals, on the front of the fuse box panel, are as just described, specifically: the left sides of the Locks, Lighter, and Chime fuses, right side of the Body fuse, and lower left corner of the Fuel Pump Relay. You should be able to easily stick either a multimeter test lead, or a test light into any of those locations to determine whether or not there is power at them. If one has power, they all should have power.

So what causes the burning and melting around Pin A5? Probably just excessively high current. The current ratings of the 4 fuses add up to 60 amps. Then there is whatever power the Fuel Pump Relay draws. If all those items are drawing power simultaneously, the current through Pin A5 could be quite high. If you use your cigarette lighter a lot, that could explain the excessive heat. At any rate, I’ve found no evidence, to date, that there is any significant problem with power to, or from, Pin A5.

We have suffered the identical failure with three identical fuse boxes, and in each of those cases, the cigarette lighter still worked. The radio and ignition, however, did not work. Clearly, Pin A5 was not the problem in any of our three failures.

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Note added 12/20/2014: I no longer consider all the statements in this post to be accurate. For example, the statement in the previous paragraph that the cigarette lighter still worked is probably incorrect. I believed it at the time, but I no longer do. In other words, I now consider that Pin A5 (AKA F5) was actually the problem in all three of the fuse boxes discussed here. But it was just too well camouflaged by its intermittent nature for me to get it 100% right at the time. So, before you even consider going to the extreme of opening up the fuse box and soldering the internal connections as shown herein, make sure you take a look at References 1 and 3, (“… Redux” and “… Part 3”) shown at the very top of this post.

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Now for a little full-frontal nudity:

This is the same fuse box as shown in the first photo, but with all the frontal components removed. Notice the numerous brass connectors showing through the holes. And they are brass, BTW. I found that out the hard way when I dropped one into an inaccessible hole underneath my desk, couldn’t retrieve it with a long magnet, and then spent over an hour figuring out how to get it. I did get it.

Here is the same fuse box with the front cover removed:

Notice the brass connectors that were visible through the holes in the previous photo.

Here is that same fuse box from a different perspective:

Yes, this is another one of those “hanging from the ceiling” shots. Notice that the plastic plate on the back side of the fuse box has been partially removed; you can see bare copper wires that have been ripped out of place. Pretty darned hard to tell where those wires belong when it comes time to put this thing back together, so be very, very, careful.

Before I ever started to take any of these fuse boxes apart, I spent dozens of hours tracing their internal connections with my multimeter to see what was connected to what . That resulted in a rather large Excel spreadsheet, with over 160 rows and columns, detailing the internal connectivity of the fuse box, along with two other spreadsheets of equal size, specially-designed to error-check the first one.

If you’re going to repair one of these fuse boxes, there is zero room for error. You really must know what connects to what before you tear into the thing. If you’d like a copy of my spreadsheets, e-mail me (thosbryant@gmail.com) and I’ll send you a copy. Just remember that my spreadsheets are specific to these two GM part numbers: 21024337 and 21024757. The internal connections and the pins on those two fuse boxes are identical in all respects, and they’re completely interchangeable. They may or may not match any other years and models of Saturns that have a different part number on the fuse box.

If you’d like to purchase one of my two spares, that’d be fine by me. Or, if you’d like to send me your fuse box for repair, I can do that, too. I would estimate, now that I have the learning curve mostly behind me, that it would probably take me the better part of two days to repair another fuse box. It is not something that I would do cheaply.

Here’s that same fuse box after removing the rear cover:

Notice all those ugly bare wires running about, many of which have been dislocated. It’s not easy to know what connects to what. Fortunately, I have my spreadsheet to tell me what used to be. I also have two other fuse boxes, with identical wiring, to take a look at, if necessary. That was a big help, being able to grab an undisturbed fuse box for comparison when I got stuck on some piece of wiring.

Here’s a shot of one of those other fuse boxes:

This is the “front” side of a 1999 fuse box, the side that faces the passenger’s footwell, the side that has all the relays and fuses stuck into it, and “top” is at the top of the photo. The right side of the photo goes toward the front of the car.

The Fuel Pump and HVAC Blower Relays plug into the connectors at the lower right. The fuses plug into the connectors above the relays. The 20 amp Cigarette Lighter fuse plugs into terminals in the 5th row from the bottom, 3rd and 4th connectors from the right side, Pins D5 and E5.

Here’s the same thing, from a slightly different perspective:

Here, I’m starting disassembly of the 1998 fuse box:

This is the back side, with “top” of the fuse box toward the top of the photo, and Pin A5 on the left. No melting around this particular Pin A5. No melting, yet this fuse box suffered from the same electrical problem as did the other two that did have melting at Pin A5.

Here’s a frontal shot of that 1998 fuse box:

Here’s the same thing, after a bit more disassembly:

Yes, this is one of those “hanging from the ceiling” shots. It’s been rotated 180 degrees to show the top of the fuse box at the top of the photo.

Here’s a view of the front of a 1999 fuse box, with the “lid” removed and flipped up:

Some of the wires remain stuck to the pins, some to the “lid”, and some have just fallen out. Pretty hard to know what goes where, especially when they fall out completely. So make sure you know what’s what before you take that lid off.

Here’s the same lid, and in the same perspective, as in the previous photo:

This is probably the only photo in this post that has the top of the item at the bottom of the photo. That’s because you have to mentally flip this one down and back onto the fuse box in the next photo.

Notice how the factory runs bare copper wires through tight-fitting grooves in the “lid”. Then the factory presses the lid down over the pins, and the wires are forced down into the V-grooves. No solder is applied at the factory. Eventually these connections fail, leaving you with a car that just doesn’t run. There’s no good way to determine exactly which connection has failed, let alone repair just the one. So, I took the whole thing apart and fixed all the connections. Soldered them all.

Here’s the front of the fuse box again, same perspective as the next-to-previous photo, just a close-up:

Notice how the silver-gray pins all have V-grooves and some have wires, whereas the brass-colored pins don’t even have a V-groove.

For example: This is a view of the front side of the fuse box, so Column A is at the far right, Column T is at the far left, and Row 1 is at the bottom. Now, compare the two brass-colored pins, located at positions O2 and R2 with the two silver-gray pins between them, at positions P2 and Q2. Another pair that clearly shows the difference is located at positions G1 (brass-colored) and H1 (silver-gray).

The four silver-gray pins at the upper left corner are somewhat special. The top two are a coupled pair, as are the lower two. Most of the silver-gray pins are singletons, not connected to any other pins, except via the copper wires, but there are some pairs that are joined together, made from a single piece of steel; you can see the connection between them. There are other examples; one such example is located at positions E1 and F1.

There’s no provision for re-wiring the brass-colored pins. They are what they are, and they should never fail, electrically. The connections between the brass-colored pins are made through the brass-colored metal pieces seen through the rectangular openings in the plastic base plate. You can’t change those connections, at least not easily, and there’s not much reason to want to.

Also, there’s no connection between any of the brass-colored pins and any of the silver-gray pins. Each set of pins is completely independent of the other set. The only connectivity between the two sets of pins is through either the external wiring connected to the back of the fuse box, or through the relays and fuses on the front of the fuse box.

Here’ a wider view of the same stuff, this time showing two fuse boxes:

Both fuse boxes are from a 1999 Saturn. One has not yet been opened up, just to be sure I have an undisturbed one for comparison purposes, if I should need it later.

Here’s another shot of those same two fuse boxes:

Once again, the above is a view of the front of the fuse boxes. Note that wires that were still in the “lid” in the previous photo, as well as all the other original wires, have now been re-installed in their proper locations in the lower fuse box.

After properly reconnecting all the wires on both sides of the lower fuse box, and then carefully checking that all connections were as prescribed by my very carefully constructed and quintuple-checked Excel spreadsheet, I then disassembled the other 1999 fuse box (the top one in the photo) and used the lower one as guidance for repairing the top one. Later, I used the top one as guidance for repairing the lower one. Ultimately, I also repaired the 1998 fuse box, again using one of these two for guidance.

Here’s a view of the front side of a 1999 fuse box after repairs were completed:

Existing wires were re-used where there seemed to be no danger of shorting. I took a thin flat screwdriver blade and ground it thinner so that it would fit into the V-grooves, then used that to drive all the wires down to the bottom of the V-grooves; that’s necessary to decrease interference between the solder and the “lid”, making reassembly easier.

The white, insulated, 20 gauge copper wires were used to replace wires that were in danger of shorting out somewhere along their path. A hacksaw blade and a thin file were used to cut grooves here and there in the plastic to provide sufficient room for the insulated wires.

I used a pair of needle nose pliers to squeeze the V-grooves tighter around the wires, which helped to ensure that the pins would fit through the slots in the “lid”. Then, all the wiring connections were soldered with rosin core electrical solder.

Super glue was used to ensure that all the wiring stayed in place so it didn’t vibrate and wear against metal components. A bit of “Household Goop” was used on a few of the bare copper wires, just to make sure they stayed in place, and to prevent vibrations which could eventually break wires at the solder connections.

The “lid” lacked sufficient room for the soldered connections to the pins, so I used my Dremel tool and a carbide bit to cut away sufficient material from around the pins to permit the lid to fit over the soldered wire connections. Those gouges are visible in the above picture. Having previously pushed the copper wires down to the bottoms of the V-grooves reduced the size of the gouges necessary to make room for the soldered connections.

Here’s the back side of the fuse box after the same treatment.:

This time I used red wires, just to make one side easily distinguishable from the other. This “lid” has also been gouged out to make room for the soldered connections.

Note that you should use only 20 gauge wire in making this repair. I initially tried some 18 gauge wire that I had on hand, but it was too big to fit in the V-grooves, and the wire was also too big to be easily routed around inside the fuse box. Took up too much space.

I tried a local electrical wholesaler for the 20 gauge wire, but they didn’t have any. They’d have been glad to order me some, but I’d have had to order a minimum of 250 feet. I traipsed over to my FLHS (Roger’s Hardware, Bath, Maine) and bought 24 feet from their in-store stock. Cost me something like 40 cents per foot for a 3-strand length. That’s 72 feet of wire, altogether, for about 10 bucks. I have plenty of leftover wire to do more of these things with.

I repaired the other 1999 fuse box the same as shown above.

I then disassembled and repaired the 1998 fuse box using only the original bare copper wires and plenty of “Household Goop” to hold the wires in place so they wouldn’t short out. I tried that as an experiment because there was less plastic inside the fuse box and more opportunity to put glue here and there. It worked out okay, but I had a hard time keeping the glue off the connector pins. It took me a long time to clean up what little glue did get on the pins. All in all, I think it would have been easier to just run the insulated wire instead.

So, there you have it, you now know how to repair the fuse box in your Saturn.

First off, thank you for your prompt call back on the matter of the F5 fuse jumper. I manage to do the job myself and I’m happy to inform that I was successful in getting that accomplished. It worked. After 8 months of trying everything to no avail. It was my last hail Mary and by chance i ran into your posting. The Saturn started right up. Thank you so much, you sir are a life saver. thank you.

For anyone else out there who’s having “F5” troubles: Please make sure you read “… Redux” and “… Part 3” to see if a simple jumper wire will fix your problem. Probably about 99% of the time, the fix shown in this, my original, posting on this subject is pure overkill, and there will be no need to go inside the fuse box as shown in this post.